document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=363826>Question 363826</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A business school claims that the average income of graduates of this school three years after graduation is $700.<BR>\n" );
document.write( "a.	If the claim is correct and if incomes are normally distributed with a standard deviation of $60, what is the probability that 36 randomly selected graduates have an average income of less than $675?<BR>\n" );
document.write( "b.	If a random sample of 36 graduates had an average weekly income of $675, what would you conclude about the validity of the claim?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #259469 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=259469\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A business school claims that the average income of graduates of this school three years after graduation is $700.<BR>\n" );
document.write( "a. If the claim is correct and if incomes are normally distributed with a standard deviation of $60, what is the probability that 36 randomly selected graduates have an average income of less than $675?<BR>\n" );
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document.write( "t(675) = (675-700)/[60/sqrt(36)] = -2.5<BR>\n" );
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document.write( "P(x-bar < 675) = P(t < -2.5 when df=36) = tcdf(-100,-2.5,35) = 0.0086<BR>\n" );
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document.write( "b. If a random sample of 36 graduates had an average weekly income of $675, what would you conclude about the validity of the claim?<BR>\n" );
document.write( "Pretty rare occurrence.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
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